<sect2 id="calc-sidereal">
<title>Sidereal Time module</title>
<indexterm><primary>Tools</primary>
<secondary>Astrocalculator</secondary>
<tertiary>Sidereal Time module</tertiary>
</indexterm>

<screenshot>
<screeninfo>The Sidereal Time calculator module </screeninfo>
<mediaobject>
  <imageobject>
    <imagedata fileref="calc-sidereal.png" format="PNG"/>
  </imageobject>
  <textobject>
    <phrase>Sidereal Time</phrase>
  </textobject>
</mediaobject>
</screenshot>

<para>This module converts between <link linkend="ai-utime">Universal Time</link> and Local <link linkend="ai-sidereal">Sidereal Time</link>. First, select whether you will use Universal Time or Sidereal Time as an input value in the <guilabel>Input Selection</guilabel> section. You must also specify a geographic longitude, and a date for the calculation, in addition to either the Universal Time or the Sidereal Time value. When you press the <guibutton>Compute</guibutton> button, the corresponding value for the other Time will be displayed. </para>
</sect2>
